The invention concerns a mounting device for argicultural spreading machines which has an upright frame equipped with means for coupling it to the toplink and to the lift arms of the three-point hydraulic lift of a tractor, on which a spreading machine driven by the tractor power takeoff shaft and provided with outlet openings can be mounted and can be raised and lowered by means of a hydraulic system.
A mounting device of this kind is known through German Gebrauchsmuster No. 70 19 086. In this mounting device the frame consists of an upright carrier to whose bottom end there is rotatably mounted an intermediate shaft which, when the mounting means is in the working state, is attached for power transmission to the tractor power takeoff shaft through a universal shaft on the one hand and on the other hand to the drive shaft of the mounted spreading machine through a belt or chain drive. Furthermore, the system for holding the mounting means of the spreading machine can consist either of lift arms pivotingly disposed on the carrier or of a guide disposed displaceably on the carrier. By means of this mounting device the spreading machine is to be easy to fill with material on the one hand, and on the other hand it is to be usable at different distances above the ground, especially for the mid-season spreading of fertilizers.
Regardless of which embodiment of this known mounting device is used, it has the disadvantage that its use is limited to a relatively narrow range of heights above the ground. For if the means for holding the spreading machine consists of lift arms, even in the event of a slight change in the operating level of the spreading machine, not only is there a change in the distance, but also there is an axial displacement of the two shafts of the belt or chain drive with respect to one another, so that, even if it is equipped with a tightening device, this drive loses its ability to operate. If, however, the holding means has a displaceably disposed guide, the two shafts of the belt or chain drive would have to be carried past one another laterally from the upper operating position through the normal operating position to the lowermost operating or loading position. Even if this were possible, it would be necessary, for example, in the normal position of the spreading machine, for all of the distance existing between the two shafts in the upper position to be equalized by a lateral movement of the tightening means. Such a tightening means, however, in view of the safety regulations existing in all countries, would result in such complications that it could not be constructed for practical use in agriculture.
Furthermore, in the known mounting device there exists this disadvantage that, regardless of its construction, the attachment of the spreading machine to it and its removal therefrom requires a considerable expenditure of time, since for this purpose the entire chain or belt drive, at least, must be disassembled from the machine.